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| Calculating Tesla's HW3 Autonomous Obligation |
Tesla started selling cars with Full Self-Driving (FSD) computers and cameras, known as Hardware 3 (HW3), in 2019. This was the standard for all of their vehicles through 2022 until HW4 (now known as AI4) supplanted them. During the HW3 window of time, Tesla made approximately 3 million vehicles that were sold as fully FSD-ready, "all that's needed is an over-the-air update, and these cars will be able to drive themselves." Now that we're on the cusp of autonomy, are these HW3 cars an albatross around Tesla's neck or an opportunity?
At a mere 144 TOPs, it's becoming apparent that HW3 likely does not have the compute horsepower, memory bandwidth, or camera clarity necessary to achieve unsupervised FSD. So what's Tesla going to do if they achieve FSD (on AI4 or 5) but HW3 proves to be insufficient? Will they retrofit the HW3 vehicles? If so, how many cars will need to be upgraded, and how much will it cost Tesla (or you)?
Introduction
The promise of FSD is a monumental technological endeavor that goes far beyond software alone; it is inherently tied to the hardware underpinning millions of Tesla vehicles already on the road. After working with Mobileye (Autopilot 1) and Nvidia (HW2/2.5), Tesla designed their own custom chip for HW3. This marked a critical milestone in their journey. HW3 was built into all Tesla vehicles for nearly 3 years. The HW3 chip was championed as the final hardware piece necessary for full autonomy. Now, with the vast improvements in subsequent hardware generations (HW4, AI5), some owners are wondering if HW3 will be able to cross the unsupervised finish line or if it will be like trying to run Borderlands 4 on a Commodore 64.
Today, we'll examine the size of the HW3 fleet, its FSD adoption rate, the retrofit costs, and how Tesla may deal with upgrades.
The HW3 Fleet: Size and Timelines
Tesla began installing HW3 in new vehicles in April 2019 (replacing the Nvidia-based HW2.5) and continued to use HW3 in primary production until the shift to HW4 in early 2023. This production window generated a large population of vehicles. Based on cumulative delivery data, there are more than 3 million vehicles in the HW3 fleet. This is a substantial number of cars.
The following graph illustrates the estimated size of this fleet over time, factoring in the deliveries until Q4 2022, and then accounting for vehicle attrition with an age-dependent scrappage rate (4.5% annually for the first 12 years).
Tesla produced roughly 440,000 vehicles with HW2/2.5 (October 2016–early 2019) and about 4 million with HW3 (April 2019–mid/late 2023), for a combined total of approximately 4.45 million vehicles that were "FSD-ready" pre-AI4.For this exercise, we'll assume:
- FSD is solved in 2027;
- Upgrades will be required for these HW2 - HW3 vehicles;
- Upgrades will start in Q4 of 2027.
When considering how many vehicles may need to be upgraded, three additional factors must be considered: scrappage, FSD adoption, and trade-ins.
Accounting for scrappage: in 2027, these vehicles will range from 4 to 11 years old. Modern light-duty vehicles (especially Teslas) show very low early attrition. Using a realistic average annual scrappage of 2% yields a survival rate of approximately 90%, meaning about 4 million still in operation. Even using an industry-average flat 4.5% annual scrappage rate leaves 3.30 million pre-AI4 vehicles still in operation in late 2027.
Scrappage didn't significantly reduce the number of upgrades that may be required, but the FSD-adoption rate is another story. From 2019 through 2022, FSD was not available in most of the world. Tesla officially stated that, at the end of 2022, over 285,000 customers in the U.S. and Canada had purchased FSD. That's a 9% FSD adoption rate. Retrofit upgrades are only required for vehicles where the owners have purchased FSD. Applying the scrappage rates to this value brings it down to only ~225,000 vehicles requiring retrofit upgrades.
Our third factor for consideration is trade-ins. Today, if a vehicle with FSD-for-life is traded in to Tesla, when it is resold, it will no longer include FSD-for-life. The new owner can, optionally, purchase an FSD subscription. Plenty of the Tesla early adopters that purchased FSD-for-life prefer to be on the bleeding edge of technology. That means they are likely to trade in for vehicles with more range or features, like the Highlander and Juniper refreshes. This could bring our number of vehicles requiring retrofit upgrades below 200,000. Supercharging these trade-ins could be a possible solution (more on this later).
Comparing HW3, AI4, (and AI5)
| HW | Compute Power (TOPS) | Comparison to HW3 |
|---|---|---|
| HW3 | 144 TOPS | Baseline (1x) |
| AI4 / HW4 | 300–500 TOPS | Approximately 2–3.5x more raw capable (With real-world FSD inference gains typically 3–5x) |
| AI5 | 2,000–5,000 TOPS (expected) | Approximately 14–35x more capable than HW3 (based on TOPS; production expected in 2026; Elon Musk describes it as 10–40x better than AI4 overall on FSD specific metrics) |
| Overall Comparison | AI4 has approximately 3 to 5 times the compute capability of HW3. AI5 is projected to vastly exceed this, enabling advanced unsupervised FSD and Robotaxi features, though exact real-world results are yet to be seen. | |
Can HW3 Do It?
This post generally assumes that an upgrade will be required for all HW2/2.5/3 vehicles to achieve full autonomy, but it's important to acknowledge that Tesla is still trying to squeeze as much as possible out of HW3. During the Q3 2025 Tesla Earnings Call, this issue was brought up directly. Here's the response from Tesla management about the future of this massive installed base.
The company's CFO explicitly stated that Tesla is "not abandoning HW3" and offered a clear assurance to concerned customers: "We will definitely take care of you guys." Adding, "My personal daily driver is a HW3 vehicle." Furthermore, Ashok Elluswamy, VP of AI SW, noted that a lighter-weight version of FSD V14, will be coming in 2026 for HW3. This V14 "Lite" will provide owners with many the latest advancements in the supervised FSD, albeit months behind the AI4 deployment.
So, whether or not Tesla finds a way to cram all of unsupervised FSD into HW3, those vehicle owners will have a path to a fully self-driving vehicle. Next, let's look at what those upgrade options may be.
Upgrade Options & Cost
When FSD is solved (Q4 2027 in this example), let's assume the cost for parts (e.g., AI4.5 or AI5 computer & cameras) and labor to retrofit a pre-AI4 vehicle is $2,500. For customers who've already paid for FSD, Tesla has an obligation to upgrade them at no cost. For owners who have not previously paid for FSD, this upgrade cost can be rolled into the FSD subscription cost, such as offering an upgrade if you commit to or pre-pay for 2 years of an FSD subscription. However, let's look at another (more likely) option.
Tesla has offered FSD transfers (off and on) for some time now (I've even used it). Currently, Tesla is no longer offering FSD transfers, but they could bring it back in a limited fashion to mitigate this issue. For example, if Tesla offered current pre-AI4 vehicle owners with FSD-for-life vehicles a $2000 "upgrade incentive" credit towards a new AI4+ vehicle, with FSD transfer offered as an early adopter award, many owners may take them up. They'd be trading in a vehicle that's between 4 and 11 years old, and they'd drive off (or should I say ride off) in a new vehicle with more range, faster charging, better cameras, and a new, far more powerful AI computer.
Above, we had the widdled the number of required retrofits below 200,000. Let's assume that 35% to 45% of pre-AI4 owners with FSD-for-life take Tesla up on this early adopter upgrade incentive program. That brings the required retrofit number down to ~120,000 vehicles.
This incentive would mean a lower margin on these vehicles for Tesla, but it would stop their service centers from being overrun with immediate retrofit requests, while being cheaper than performing retrofits.
Above, we initially estimated that there would be 225,000 vehicles requiring retrofits. If Tesla had to upgrade all of these at $2500 each, the total cost would be $562,500,000. However, Tesla can reduce this number by nearly 50% (down to $300 million) with time and smart trade-in trade-up incentives. This will be easy for Tesla to afford these upgrades and retrofits if they are the first company to offer for sale vehicles that allow you to sleep, work, or play while the vehicle drives you around, and FSD vehicle orders are pouring in.
FSD Adoption and Pricing Post-Solution
Once FSD is truly solved, the perceived value of Tesla's vehicles and FSD stack will fundamentally change. FSD will transform from an advanced driver-assistance system into a fully validated eyes-off, hands-off system. This will allow you to reclaim your time or just look out the window while your car chauffeurs you. Unsupervised FSD will also be a robotaxi enabler, allowing owners to put their cars into service to generate revenue. This certainty will dramatically increase both the adoption rate and the FSD sale price.
We can conjecture the following changes:
- Price Increase: The subscription price of FSD (currently $99/month) will increase significantly. Unsupervised FSD is the "killer app" for cars, and the subscription price is likely to skyrocket. An initial price of $500 per month is a real possibility. It's even possible that, after general unsupervised FSD is solved, vehicles with FSD-for-life become highly sought after.
- Adoption Rate Increase: As soon as FSD is solved, the hesitancy surrounding the low adoption rate (9 to 12%) will evaporate. Customers will recognize FSD as a utility or an investment, pushing the take rate on all new vehicles to 50% in 2028 and eventually above 80% in following years.
- Retrofit Demand: Every Tesla built since October 2016 has the camera placements to allow retrofits to a new FSD system. The HW2, 2.5, and 3 fleet comprises ~4.45 million vehicles. This vast population of existing non-FSD-equipped vehicles would become the target of a massive upgrade demand. The potential FSD revenue from these post-upgrade vehicles would quickly eclipse the $300 million cost of "free" retrofits.
Crisitunity
| Vehicles | Count |
|---|---|
| Native HW3 | ~4 million |
| HW2/2.5 upgraded to HW3 | 70,000 |
| HW3 already with FSD | 285,000 |
| HW3 vehicles that Tesla will be obligated to retrofit Due to owners not upgrading to AI4+ |
125,000 |
| HW2/2.5/3 FSD Potential Adoption | 2,740,000 |
A naïve analysis might look at the 4+ million HW3 vehicles and see an obligation to upgrade these to FSD-ready on Tesla's dime. Millions of cars, costing thousands of dollars each, would be a huge liability for any company. However, the opposite is true. Only a small percentage (~9%) of these were purchased with FSD. Of those, many have (or will) upgrade to a vehicle with newer native HW and transfer FSD. This leaves the vast majority of the HW3 fleet (97%) with no obligation for free retrofits. And each of these vehicles in the 97% can be converted to a self-driving car if the owner subscribes to FSD at the higher 2028 price (which more than pays for the retrofit expense).
Conclusion
Our analysis of the pre-AI4 fleet highlights a moment of both challenge and opportunity for Tesla. The obligation to provide hardware retrofits to tens of thousands of customers who paid for FSD is a substantial financial undertaking, yet one to which Tesla management has committed. The explicit promise made during the Q3 2025 earnings call, "We will definitely take care of you guys," codifies the company's intent to fulfill the original FSD promise. The early adopters paid for the development of the technology, and there are multiple ways to reward them for this leap of faith without being financially ruinous.
Early adopters helped pay the cost and provided data for unsupervised FSD development, allowing Tesla entry into the vast autonomy market that this technology unlocks. This retrofit commitment, coupled with the development of the V14 "Lite" to retain HW3 owners in the ecosystem until a complete solution is developed, ensures that the HW3 fleet remains an active and valuable part of the effort. The hardware retrofit, while costly, will be swiftly offset by the massive increase in FSD adoption rate and the resultant multiplication of the FSD purchase price. This transforms the pre-AI4 legacy fleet from a liability into a highly valuable, revenue-generating asset that paves the way for a more sustainable future of shared autonomous mobility. The proactive communications from the company, especially regarding their promise not to abandon HW3, are essential for maintaining customer trust throughout this transition period.
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Edit: Originally published November 5th, 2025. Updated Sept 2026 to note that FSD is no longer for sale; it is now subscription-only. Clarified the trade-in/trade-up program and other updates.








